Generally, by organizing multiple disks into a disk array according to a certain pattern and scheme, it may possible to obtain a higher speed, better stability and larger storage capacity than a single disk. With disk capacity growing, data reconstruction time for a disk array, for example, a Redundant Array of Independent Disks (RAID) may become longer and longer.
For example, FIG. 1 shows trends of reconstruction time for serial advanced technology attachment (SATA) disks of different capacities in DDR. As shown in FIG. 1, it takes more than 14 hours for a 4 TB SATA disk to finish data reconstruction without any file system input/output (I/O) interference.
Longer reconstruction time may mean higher data loss risks, which may make RAID unavailable in large scale storage application area. Additionally, data reconstruction and file system I/O's may affect each other. Longer reconstruction time may make file system performance worse. On the other hand, heavy file system I/Os may make reconstruction time longer.